Methods for Escherichia coli identification in food, water and clinical samples based on beta‐glucuronidase detection

Frampton, E. W.; Restaino, L.

doi:10.1111/j.1365-2672.1993.tb03019.x

Cited by 91 publications

(63 citation statements)

References 97 publications

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“…Furthermore, studies have been performed on the GUD activities of the Enterobacteriaceae and E. coli and confirmed that GUD activity was mostly limited to (Kilian and Bülo 1976). In the Enterobacteriaceae genus, only 20% to 29% of the Salmonella isolates tested showed GUD positive activities (Kilian and Bülo 1976;Massenti et al 1980;Feng and Hartman 1982;Frampton and Restaino 1993).…”

Section: Specificity Of Mug Assays For the Detection Of Non-target Bamentioning

confidence: 92%

“…In contrast, GUD activity is less common in other Enterobacteriaceae genus, such as Shigella (44 to 58%), Salmonella (20 to 29%) and Yersinia strains and in Flavobacteria (Kilian and Bülo 1976;Feng and Hartman 1982;Hartman 1989;Frampton and Restaino 1993). GAL catalyzes the breakdown of lactose into galactose and glucose and has been used mostly for enumerating the coliform group within the Enterobacteriaceae family.…”

Section: Bacterial Cell Enzymes As Biosensing Materialsmentioning

confidence: 99%

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A biosensor platform for rapid detection of E. coli in drinking water

Hesari

Alum

El-Zein

et al. 2016

Enzyme and Microbial Technology

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The need for rapid, specific and sensitive assays that provide a detection of bacterial indicators are important for monitoring water quality. Rapid detection using biosensor is a novel approach for microbiological testing applications. Besides, validation of rapid methods is an obstacle in adoption of such new bio-sensing technologies. In this study, the strategy developed is based on using the compound 4-methylumbelliferyl glucuronide (MUG), which is hydrolyzed rapidly by the action of E. coli β-D-glucuronidase (GUD) enzyme to yield a fluorogenic product that can be quantified and directly related to the number of E. coli cells present in water samples.The detection time required for the biosensor response ranged from 30 to 120 minutes, depending on the number of bacteria. The specificity of the MUG based biosensor platform assay for the detection of E. coli was examined by pure cultures of non-target bacterial genera and also non-target substrates. GUD activity was found to be specific for E. coli and no such enzymatic activity was detected in other species. Moreover, the sensitivity of rapid enzymatic assays was investigated and repeatedly determined to be less than 10 E. coli cells per reaction vial concentrated from 100 mL of water samples.The applicability of the method was tested by performing fluorescence assays under pure and mixed bacterial flora in environmental samples. In addition, the procedural QA/QC for routine monitoring of drinking water samples have been validated by comparing the performance of the biosensor platform for the detection of E. coli and culture-based standard techniques such as Membrane Filtration (MF). The results of this study ii indicated that the fluorescence signals generated in samples using specific substrate molecules can be utilized to develop a bio-sensing platform for the detection of E. coli in drinking water. The procedural QA/QC of the biosensor will provide both industry and regulatory authorities a useful tool for near real-time monitoring of E. coli in drinking water samples. Furthermore, this system can be applied independently or in conjunction with other methods as a part of an array of biochemical assays in order to reliably detect E. coli in water.

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Section: Specificity Of Mug Assays For the Detection Of Non-target Bamentioning

confidence: 92%

Section: Bacterial Cell Enzymes As Biosensing Materialsmentioning

confidence: 99%

A biosensor platform for rapid detection of E. coli in drinking water

Hesari

Alum

El-Zein

et al. 2016

Enzyme and Microbial Technology

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“…For the foreseeable future, the faecal coliform test will continue to be the basis for much of the regulatory decision making regarding both quality water harvesting and contact recreation. 78 The primary bias of using culturable tests in isolating E. coli as an indicator organism, has being overcome by using PCR, which detects both live and dead bacteria. 76 The PCR is a rapid and reliable tool for the molecular-based diagnosis of a variety of infectious diseases.…”

Section: Current Trends Of E Coli As Indicator Organismmentioning

confidence: 99%

Escherichia coli as an indicator of bacteriological quality of water: an overview

Odonkor

Ampofo

2013

Microbiol Res (Pavia)

325

192

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Monitoring the microbiological quality of drinking water relies largely on examination of indicator bacteria such as coliforms, Escherichia coli, and Pseudomonas aeruginosa. E. coli is a member of the faecal coliform group and is a more specific indicator of faecal pollution than other faecal coliforms. Two key factors have led to the trend toward the use of E. coli as the preferred indicator for the detection of faecal contamination, not only in drinking water, but also in other matrices as well: first, the finding that some faecal coliforms were non faecal in origin, and second, the development of improved testing methods for E. coli. The faecal coliform definition has also been revised to coincide better with the genetic make-up of its members and now includes newly identified environmental species. As a result, faecal coliforms are increasingly being referred to as thermotolerant coliforms. This, combined with improved detection methods for E. coli, has started a trend toward the use of E. coli in place of thermotolerant coliforms as a more reliable indicator of faecal pollution in drinking water. At present, E. coli appears to provide the best bacterial indication of faecal contamination in drinking water. This is based on the prevalence of thermotolerant (faecal) coliforms in temperate environments as compared to the rare incidence of E. coli, the prevalence of E. coli in human and animal faeces as compared to other thermotolerant coliforms, and the availability of affordable, fast, sensitive, specific and easier to perform detection methods for E. coli.

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“…However, this enzyme activity has been detected with non-E. coli species, including members of the Enterobacteriaceae (i.e., Escherichia vulneris [28,57] and Shigella [40 to 67%] [28,58,59], Salmonella [17 to 29%] [58,60], Yersinia [61][62][63], and Citrobacter, Enterobacter, Edwardsiella, and Hafnia [37,61,62,64,65] spp.) and bacteria outside the family Enterobacteriaceae (i.e., (12).…”

Section: Figmentioning

confidence: 99%

Phenotypic and Phylogenetic Identification of Coliform Bacteria Obtained Using 12 Coliform Methods Approved by the U.S. Environmental Protection Agency

Zhang

Hong

LeChevallier

et al. 2015

Appl Environ Microbiol

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The current definition of coliform bacteria is method dependent, and when different culture-based methods are used, discrepancies in results can occur and affect the accuracy of identification of true coliforms. This study used an alternative approach to the identification of true coliforms by combining the phenotypic traits of the coliform isolates and the phylogenetic affiliation of 16S rRNA gene sequences with the use of lacZ and uidA genes. A collection of 1,404 isolates detected by 12 U.S. Environmental Protection Agency-approved coliform-testing methods were characterized based on their phylogenetic affiliations and responses to their original isolation media and lauryl tryptose broth, m-Endo, and MI agar media. Isolates were phylogenetically classified into 32 true-coliform, or targeted Enterobacteriaceae (TE), groups and 14 noncoliform, or nontargeted Enterobacteriaceae (NTE), groups. It was shown statistically that detecting true-positive (TP) events is more challenging than detecting true-negative (TN) events. Furthermore, most false-negative (FN) events were associated with four TE groups (i.e., Serratia group I and the Providencia, Proteus, and Morganella groups) and most false-positive (FP) events with two NTE groups, the Aeromonas and Plesiomonas groups. In Escherichia coli testing, 18 out of 145 E. coli isolates identified by enzymatic methods were validated as FN. The reasons behind the FP and FN reactions could be explained through analysis of the lacZ and uidA genes. Overall, combining the analyses of the 16S rRNA, lacZ, and uidA genes with the growth responses of TE and NTE on culture-based media is an effective way to evaluate the performance of coliform detection methods. Total coliform bacteria and Escherichia coli are considered costeffective bacterial indicators for the protection of public health. Detectable total coliforms indicate potential contamination associated with the water distribution system, while E. coli is a good indicator of fecal contamination, with a health goal (i.e., maximum contaminant level goal [MCLG]) of zero under the Revised Total Coliform Rule (RTCR) (1). When a positive result of total-coliform testing is observed, public water systems (PWSs) are required to collect and analyze three repeat samples (1). A system assessment is required when a PWS exceeds a specific frequency of total-coliform occurrence. When an E. coli maximum contaminant level (MCL) violation incurs, a PWS must have an assessment performed by the state or a state-approved entity and must correct any sanitary defects (1). False-positive (FP) results for either total-coliform or E. coli tests impose an unnecessary burden on water utilities. On the other hand, false-negative (FN) results expose consumers to potential health threats and delay response times for effective action. Therefore, accurate detection of total coliforms and E. coli in drinking water systems is crucial for both water utilities and consumers.To date, the U.S. EPA has approved 12 methods for the detection of coliform bacteria i...

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Methods for Escherichia coli identification in food, water and clinical samples based on beta‐glucuronidase detection

Cited by 91 publications

References 97 publications

A biosensor platform for rapid detection of E. coli in drinking water

A biosensor platform for rapid detection of E. coli in drinking water

Escherichia coli as an indicator of bacteriological quality of water: an overview

Phenotypic and Phylogenetic Identification of Coliform Bacteria Obtained Using 12 Coliform Methods Approved by the U.S. Environmental Protection Agency

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